The invention relates to a control circuit for a zooming device, in which processes for moving a group of zoom lenses (hereinafter referred to as "a zoom lens assembly" when applicable) to a desired one of a number of magnificaton positions (200 for instance) are controlled by a microcomputer.
A conventional processing circuit of this type is assembled from TTL or CMOS logic circuits. The physical size of such a processing circuit for moving a zoom lens assembly to a number of (for instance, more than 200) magnification positions is ordinarily large, and it is considerably difficult to simply increase or change the functions thereof.
Due to recent developments in semiconductor manufacturing techniques, microcomputers capable of performing calculations or other operations with one or several chips have become available. With the processing circuit being constituted with such a microcomputer with suitable software provided, the circuit can be easily miniaturized and the functions thereof can be readily increased or changed.